Sine bar attachment



June 13, 1950 MCDOWELL 2,511,443

SINE BAR ATTACHMENT Filed April 11, 1946 Patented June 13, 1950 UNITEDSTATES PATENT OFFICE 1 Claim.

This invention relates to precision instruments, and more particularlyto an instrument for setting tapers to a high degree of accuracy onvarious machines.

The object of the invention is to provide an instrument of the typeindicated of rigid construction but capable of easy assembly andadjustment with parts capable of use for various purposes whendisassembled.

The invention consists in the novel construction, arrangement andcombinations of parts hereinafter more particularly described andclaimed.

One sheet of drawings accompanies this specification as part thereof inwhich like reference characters indicate like parts throughout.

In the drawing:

Fig. 1 is a side elevation of the improved instrument.

Fig. 2 is a plan view.

Fig. 3 is an end elevation.

The present instrument belongs to that general type in which straightedges are assembled with standard sine blocks by means of which theangularity of the straight edges is accurately determined.

In accordance with the present invention, a mandrel part I is providedherein illustrated as cylindrical in shape having axially disposedcenter bores 2-2 at either end and one planar true face 3 extending inthe illustrated embodiment from one end through the major length of themandrel. Adjacent the other end a transverse arcuate bearing 6 isformed, the axis of the arc of said bearing extending parallel with thesurface of the true face 3 and perpendicular with respect to the longaxis of the mandrel I. The mandrel may, of course, :be square, octagon,or any desired cross-section.

A sine bar 8 is provided having a planar true face and also formed ateach end with cut away seats for roller members 'l1'. The seats forthese rollers, it will be noted, are formed at one end by theperpendicularly disposed faces 9 and at the other end by theperpendicularly disposed faces Hl and the rollers '|1' which are ofcylindrical form are secured in fixed relationship to the sine bar 8 asby screws 9.

The sine bar 8 is further provided with a medial transverse bore adaptedto rotatively seat the reduced end portions l9|9 of two stud membersiii-4B which reduced portions l9l9 are formed respectively withcomplementary threaded stud and socket 20 by means of which the studmembers 18-18 are secured together and rotatively mounted with respectto the sine bar 8. Each of the stud members it is provided with atransverse bore through which is rotatively mounted an adjustment screwI! which screws I! are held in rotative relationship with the studs [8by an annular groove formed on the member I! and a transverse pin 26extending through the stud l8.

A sleeve member 4 having an orifice conforming in shape with the mandrell is slidably mounted on said mandrel and provided with a set screw H bymeans of which said sleeve can be held in adjusted position on themandrel. Diametrically disposed orifices are provided one on either sideof the sleeve 4 in which orifices I5 are rotatively mounted studs l2|2which studs are held in position by means of an annular groove and crosspin 16. The outer ends of the studs l2 are provided with knobs l3 havingthreaded orifices complementary to the threaded stems M of the screws11.

The sine block is further provided intermediate its ends with atransverse bore adapted to receive a stud 2! upon the outer end of whichis positioned a transverse frame 22 carrying a level 23.

In assembling the instrument the sine bar 8 having rigidly associatedtherewith the transverse cylindrical bearing members 1-1, is placed onthe mandrel with the bearing roller I seated in the transverse bearingseat 6. The screws M are then threaded through the studs l3 and thesleeve 4 adjusted lengthwise of the mandrel l, to provide the mostconvenient bearing for the sine bar in connection with the particularangle to which the instrument is being adjusted. Thereafter, sine blocksS indicated for that particular angle, are placed on the true face 3 ofthe mandrel directly under the roller bearing 1 and the screws I1tightened down to rigidly associate the sine bar 8 with the mandrel I.In this position the true faces 3 and 5 will conform with the angle ofthe sine blocks S. The instrument can then be placed in a lathe or othermachine tool with the centers of the machine engaging the centerbearings 2-2 of the mandrel.

When disassembled, the sine bar 8 is available for use in various waysin setting up work on a bench.

Having thus fully described my invention, I claim:

Taper setting instrument comprising a mandrel having axially alignedcentering holes in its ends and a true planar face extending parallelwith its axis, said mandrel further formed with 3 a transverselydisposed roller bearing adjacent one end, a sine bar formed with alongitudinally extending true face, with oppositely disposed rollerseats adjacent each end, roller elements fixedly seated one in eachroller seat on the sine bar and means longitudinally adjustable on themandrel for securing the sine bar in angularly adjusted relation to theaxis of the mandrel with one roller seated in the roller bearing of themandrel and the other roller contacting a standard sine block seated onthe true face of the mandrel, said means comprisin a carriage embracingand slidable longitudinally on the mandrel, means for securing thecarriage in adjusted position on the mandrel, studs swiveled on thecarriage to turn on an axis perpendicular to that of 4 face, the studson the mandrel carriage having through threaded passages, and threadedadjustment bolts swiveled in the swivel studs of the sine bar andthreaded through the threaded pas- 5 sages of the swivel studs of thecarriage.

axis perpendicular to the long axis of its true LAWRENCE MCDOWELL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,683,509 Wescott Sept. 4, 1928uesses Boos June 24, 1930 1,931,730 Klay Oct. 24, I933 2,39 i, -1 2 1Silvermaster Apr. 9, 1946 2,446,562 'Irobojevich Aug. 10. 1948

